1. Field of the Invention
This invention is directed toward an improved measuring roller system. The invention is more particularly directed toward an improved measuring roller system used in tree processing machines for measuring a length of tree processed by the machine.
2. Description of the Related Art Including Information Disclosed Under CFR .sctn..sctn.1.97-1.99
Measuring roller systems are presently employed on tree processing machines to measure the length of a least a section of the tree being processed by the machine. The systems include a measuring roller which is usually toothed to bite into the tree to minimize slippage. A sensor arrangement measures the amount of rotation of the roller as it is rotated by a tree being fed past the roller by the machine, and this amount of rotation is converted to provide a measure of length of the tree fed past the roller.
A tree being processed, such as when it is being delimbed, is held by gripping arms on the machine and feed rollers feed the tree through the gripping arms to delimb it. The measuring roller is usually mounted at the ends of swinging arms on the machine and is biased against the tree as the tree is fed by the feed rollers past the measuring roller. Problems arise when the tree being fed changes position to move toward or away from the measuring roller simultaneously with being fed in an axial direction past the roller. This position change occurs because the tree is not always symmetrical and the gripping arms can change the position of the tree as they regrip the tree due to changes in the cross-section of the tree as it is being fed axially. The position change of the tree can cause inaccurate measuring of the length of the tree. The inaccurate measurement occurs because as the tree moves in a transaxial direction relative to the roller, it causes the roller to swing relative to the frame of the machine. As the roller swings, it also rotates slightly in one direction or the other. This rotation is incorrectly picked up by the stationary sensor arrangement as axial movement of the tree when in fact the rotation is due to transaxial movement.